This invention relates to labor saving devices for the movement of heavy objects, particularly to devices for lifting and movement of lateral file cabinets from place to place or onto and from truck transportation means.
Lateral file cabinets having pull out shelves that slide on roller tracks mounted in a cabinet frame are widely used in modern business offices. A typical lateral file cabinet has two or more slide or roller track mounted shelves vertically disposed one over the other and arranged to move out of the cabinet to a side of the cabinet frame for insertion and removal of individual files. Such file cabinets are often preferred over traditional vertical file cabinets having file drawers mounted on slide or roller tracks for movement out of an end of the cabinet for use. Lateral file cabinets often provide space saving and access advantages over such traditional file cabinets.
Movement of file cabinets is often required either within an office building manually or from building to building on a moving van or truck. Vertical file cabinets typically have a depth of thirty inches or less, a width of eighteen inches or less and a height of six feet or less. The cabinets are constructed of sheet metal over a relatively rigid steel frame. Such cabinets can be lifted and moved with relative ease by one person using a manual two wheel dolly. If weight reduction is necessary, entire drawers with contents intact can be removed and transported separately.
Lateral file cabinets are typically twenty-four to forth-eight inches in length, sixteen to twenty inches wide and thirty to seventy-two inches or more in height. These cabinets are also constructed of sheet metal over a steel frame. However, the open side required for the laterally slidable file shelves results in a less rigid cabinet structure than that of the vertical file cabinets. Care must exercised in moving these lateral file cabinets, particularly fully loaded cabinets, because the steel frame can easily distorted, causing permanent bending of the slides or roller tracks and track supports. Because file shelves are typically not removable, files and other shelf contents must be individually removed if weight reduction is desired to avoid distortion of the frame during lifting and moving. Removal of individual files or other shelf contents to reduce the weight greatly increases the labor expense and time required to move a lateral file cabinet. Elimination of the contents removal step is desirable. But the greater length and less rigid construction of lateral file cabinets makes lifting and movement of fully loaded cabinets by use of two-wheel dollies impractical. A loaded file cabinet cannot be railed or carried on such a dolly without frame distortion.
One solution for movement of fully loaded lateral file cabinets is provided by a portable crane having a vacuum pump and suction cup on a hydraulic powered arm for lifting an entire lateral file onto or from a four-wheel dolly. The top surface of the lateral file cabinet is gripped by the suction cups and the entire cabinet is lifted by the hydraulic powered arm. Such a portable crane is expensive and of such size as to be unweildy in many offices, even to the point of being too large to use in cases of limited space around the cabinet. The expense of outfitting a moving crew with such a crane, the great amount of time required to move a cabinet with such a crane and the space occupied in the moving truck by the crane are economic disadvantages. Lifting a cabinet from the top in such manner can distort the frame of some cabinets and say damage the sheet metal top. A means of lifting and moving fully loaded lateral file cabinets with inexpensive, time-saving and safe manual means is clearly desirable.